The sense of agency is the perception of willfully causing something to happen. Wegner and Wheatley proposed three prerequisites for SA: temporal contiguity between an action and its effect, congruence between predicted and observed effects, and exclusivity . We investigated how temporal contiguity, congruence, and the order of two human agents’ actions influenced SA on a task where participants rated feelings of self-agency for producing a tone. SA decreased when tone onsets were delayed, supporting contiguity as important, but the order (...) of the agents’ actions also mattered. Relative contiguity was the main determinant of SA, as delayed tones were usually attributed to the most recent action. This was unaffected by contingencies between the two actors’ actions , showing that contiguity has a powerful influence on SA, even during joint action in the presence of other cues. (shrink)

We studied how people determine when they are in control of objects. In a computer task, participants moved a virtual boat towards a goal using a joystick to investigate how subjective control is shaped by (1) correspondence between motor actions and the visual consequences of those actions, and (2) attainment of higher-level goals. In Experiment 1, random discrepancies from joystick input (noise) decreased judgments of control (JoCs), but discrepancies that brought the boat closer to the goal and increased success (the (...) autopilot) increased JoCs. In Experiment 2, participants raced to the goal against a computer-controlled rival boat while varying levels of noise interfered with each boat. Participants reached the goal more often and rated their own control higher when the computer rival had good control. Subjective control over moving objects depends partly on consistency between motor actions and their effects, but is also modulated by perceived success and competition. -/- Keywords: Control; Action; Feedback; Competition . (shrink)

Self-initiated action effects are often perceived as less intense than identical but externally generated stimuli. It is thought that forward models within the sensorimotor system pre-activate cortical representations of predicted action effects, reducing perceptual sensitivity and attenuating neural responses. As self-agency and predictability are seldom manipulated simultaneously in behavioral experiments, it is unclear if self-other differences depend on predictable action effect contingencies, or if both self- and externally generated stimuli are modulated similarly by predictability. We factorially combined variation in predictability (...) of action effects, spatial congruence, and performance by the self or computer to dissociate these influences on a visual discrimination task. Participants performed 2AFC speed judgments. Self-initiated motion was judged to be slower than computer-initiated motion when action effect contingencies were predictable, while spatial congruence influenced speed judgments only when action effect contingencies were unpredictable. Results are discussed in relation to current theories of sensory attenuation. (shrink)

The phenomenology of controlled action depends on comparisons between predicted and actually perceived sensory feedback called action-effects. We investigated if intervening task-irrelevant but semantically related information influences monitoring processes that give rise to a sense of control. Participants judged whether a moving box “obeyed” or “disobeyed” their own arrow keystrokes or visual cues representing the computer’s choices . During 1 s delays between keystrokes/cues and box movements, participants vocalized directions cued by letters inside the box. Congruency of cued vocalizations was (...) manipulated relative to previously selected keystrokes and upcoming box movements. In Experiment 1, reported obey moves and feelings of control reflected the true frequency of obey moves, but were also modulated by vocalizations. Incongruent vocalizations reduced reported obey moves, whereas congruent vocalizations increased them. In Experiment 2, vocalizations had stronger effects when their congruence with primary-task box movement was consistent for several consecutive moves before congruence changed. In Experiment 3, analogous impacts of vocalizations occurred when the computer selected the directions and participants judged whether the computer had control of the box. We conclude that predicted and perceived action-effects associated with semantically related but separate and ostensibly irrelevant actions can be conflated with one another. This interference is not restricted to actions performed with the same effector or within the same modality, or even by the same actor. Thus in estimating degrees of control, the mind integrates across ongoing action systems, whether or not they are logically task-relevant. (shrink)